Grinding and metal disintegrating apparatus



March 12, 1963 c. GARRISON 3,031,253

GRINDING AND METAL DISINTEGRATING' APPARATUS Filed Oct. 6, 1960 9 Sheets-Sheet 1 INVENTOR :7 ATTORNEY;

March 12, 1963 c. L. GARRISON GRINDING AND METAL DISINTEGRATING APPARATUS 9 Sheets-Sheet 2 Filed Oct. 6. 1960 INVENTOR ULJPPURD L. [7211mm an.

3 ATTORNEY March 12, 1963 c. L. GARRlsoN 3,081,253

' GRINDING AND METAL DISINTEGRATING APPARATUS Filed Oct. 6, 1960 9 Sheets-Sheet 4 371 A 388 v 387 3,97 n n i 370 7* M TIE-14k- 5 0 5 332 37a 2 4 a, as; m, 392 r I an sv/fi aw 367 366 INVENTOR: ELIPPURD L. EJIRHISUN.

g ATTORNEY be C. L. GARRISON GRINDING AND METAL DISINTEGRATING APPARATUS 9 Sheets-Sheet 5 March 12, 1963 c. L. GARRISON 3,081,253

GRINDING Am: METAL DISINTEGRATING APPARATUS Filed Oct. 6, .1960 9 Sheets-Sheet '7 v 0 I E I%VEN;OR I I5 Z 4:- ELIPFUHD L. Emmsim.

March 1963 c. GARRISON 3,081,253

GRINDING AND METAL DISINTEGRATING APPARATUS Filed Oct. 6, 1960 9 Sheets-Sheet 8 INVENTO R 2 ELIPFuRn L. 51112215011 United States Patent ,Dffice 3,081,253 Patented Mar. 12, 1953 3,081,253 GRINDING AND METAL DISINTEGRATING APPARATUS Cli-iforrl L. Garrison, Adrian, Micln, assignor to Oliver Instrument Company, Adrian, Mich., a corporation of Michigan Filed Oct. 6, 1960, SenNo. 60,953 20 Claims. (Cl. 204217) This invention relates to metal disintegrating and grinding machine and more particularly to an apparatus for removing metal from form cutters or multitoothed cutting tools where it is essential that the teeth of the cutting instrumental-ity be shaped or conformed to a uniform size or standard.

Cutter grinders have been devised and used for grinding teeth of rotatable cutting instrumentalities, tools or multitoothed cutters by reciprocating a ram carrying a rotating grinding wheel in engagement with successive teeth of a cutter, the path of the abrading region of the wheel being controlled by a pattern or template associated with the ram. A grinding machine of this character electrode in an electrical circuit which is reciprocable across the multitoothed cutting tool or work piece in conjunction with a reciprocable support for the metal disintegrating electrode controlled by cam means, and wherein the electrode is moved across the work piece at a comparatively low speed during an operative or metal disintegrating stroke of the electrode and the stroke speed increased during idle range of movement of theelectrode whereby the time required to perform metal disintegrating or tooth shaping operations on a multitoothed tool or cutter is greatly reduced.

Another object of the invention resides in an electric metal disintegrating system or apparatus, especially adaptable for conforming teeth of a multitoothed cutter wherein each tooth comprises two or more cutting edges in angular relation and wherein one cutting edge is acted upon by electric current through the medium of the metal disintegrating instrumentality in one direction of movement thereof, and another cutting edge of the tooth acted system for a multitoothed cutter grinding apparatus wherein the cutter is automatically indexed to bring successive teeth thereof into position to'be acted upon by the grinding or abrading means and wherein the apparatus is automatically brought to rest after all of the teeth of the cutter have been ground or conformed to a desired shape or pattern.

Another object of the invention resides in a hydraulically operated means for elevating the ram of the cutter tool processing apparatus to facilitate the interchange of templates or pattern blocks for conforming the teeth of diiferent types and sizes of cutters or cutting tools to desired shapes.

Another object of the invention resides in an improved means for positively lubricating a reciprocating component of a toothed cutter processing apparatus.

Another object of the invention is the provision of an apparatus for conforming or sharpening multitoothed cutters through the utilization of a rotating component in conjunction with electric energy conducted through the rotatingcomponent, whereby the resistance to the passage of current at a region of the rotatable component adjacent'a cuttereliects a controlled disintegration or removal of the adjacent metal of the cutter to effect a sharpening or forming of the cutter teeth to a predetermined shape orpattern.

Anotherobje'ct. of the invention resides in a cutter mounting and indexing means I for automatically advancing a cutter after each cycle of metal disintegrating or abrading operations-have been performed upon a cuttertooth until all teeth of a cutter have been processed and the apparatus automatically brought to rest.

Another object of the invention resides in anelectric metal disintegrating system or method whereina rotatable and reciprocable arbor provides a current conducting component for current supplied through a rotating instru- -mentality or electrode carried by the arbor and controlling the path of the rotatable instrumentality during flow of electrical energy therethrough for removing metal of a tool for sharpening the tool. 7

Furtherobjects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economics of manufacture and numerous other features-as will be apparent from -'a upon by current through the metal disintegrating instrumentality during a retractive stroke of the latter whereby to accurately conform both edges of each tooth by independent movements of the metal disintegrating electrode. I

Another object of the invention is the provision of an apparatus for electrically disintegrating or abrasively re moving metal of the teeth of a cutter or tool through a hydraulically controlled system whereby the eliective metal disintegrating or abrading strokes of the member are effected at proper speeds to attain most eflicient metal disintegration or removal in sharpening or conforming the teeth of a cutter.

Another object of the invention resides in an improved means for effecting relative movement between the cutter consideration of the-specification and drawing of a form of the invention, which may be preferred, in which:

FIGURE 1 is a longitudinal sectional view through one form of work performing apparatus of the invention;

FIGURE 2 is a front elevational view of the apparatus illustrated in FIGURE 1;

FIGURE 3 is a detail sectional view taken substantially on the line 33 of FIGURE 2;

FIGURE 4 is a detail sectional view taken substantially on the line 4-4 of FIGURE 2;

FIGURE 5 is a longitudinal sectional view throng the feed mechanism for the abrading wheel;

FIGURE 6 is an end view of a portion of the arrangement illustrated in FIGURE 5;

FIGURE 7 is a fragmentary sectional view taken substantially on the line 77 of FIGURE 5;

or work piece being operated upon and the metal disinte grating or abradin-g means for regulating or controlling the amount of metal removed during an operative cycle of the metal disintegrating or abrading means.

Another object of the invention embraces a control in section of a hydraulically actuated elevating for the ram construction;

FIGURE 12 is an enlarged plan view of a portion of the arrangement shown in FIGURE 11;

FIGURE 13 is a longitudinal sectional view taken substantiaily on the line 13-13 of FIGURE 11;

FIGURE 14 is a transverse sectional view taken substantially on the line 1414 of FIGURE 13;

FIGURE 15 is an enlarged sectional view of a control cam or template and reciprocating means therefor;

FIGURE 16 is a top plan view of the arrangement shown in FIGURE 15;

FIGURE 17 is a side elevational view of a fluid pressure controlled unit for shutting ofi the operating components at the completion of a cycle of operations;

FIGURE 18 is a front view of the construction shown in FIGURE 17 with the housing and certain elements shown in section;

FIGURE 19 is a longitudinal sectional view of a portion of the machine embodying means for accomplishing electric disintegration of metal of a work piece;

FIGURE 20 is a fragmentary top plan view of a means providing intermittent lubrication for the ram supporting surfaces;

FIGURE 21 is a longitudinal sectional view taken substantially on the line 21-21 of FIGURE 2O;

FIGURE 22 is a transverse sectional view taken substantially on the line 2222 of FIGURE 20;

FIGURE 23 is a detail sectional view taken substantially on the line 23-43 of FIG URE ZO;

FIGURE 24 is'a longitudinal sectional view illustrating a fluid actuator for controlling the movable cam utilized in electric disintegration of metal with'the apparatus illustrated in FIGURE 19;,

FIGURE 25 is a greatly enlarged fragmentary sectional view of a valve arrangement associated with the piston illustrated in FIGURE 24;

FIGURE 26 is a plan view of a timing unit for use with the apparatus illustrated in FIGURE 19;

FIGURE 27 is a sectional view taken substantially on the line 2727 of FIGURE 26;

FIGURE 23 is a sectional view taken substantially on the line 28-48 of FIGURE 27;

FIGURE 29 is an enlarged view of a portion of the i construction illustrated in FIGURE 27;

FIGURE 30is a schematic drawing of the hydraulic system controlling and actuating various mechanisms of the apparatus;

FIGURE 31 is a sectional view lengthwise of the ram illustrating the cam controlled path of a metal removing wheel in cutting or sharpening teeth of a multitoothed rotary cutter;

FIGURE 32 is a graphic representation of the duration of the relatively fast and slow speed periods of travel of the ram in a cycle of removing metal from a tool by electric disintegration, and

FIGURE 33 is a fragmentary view of a cutter tooth processed or sharpened through the use of the apparatus of the invention.

The method and apparatus of the invention are especially usable for disintegrating, grinding or abrading metal of work pieces, such as multitoothed cutters, for

accurately conforming or sharpening teeth of cutters to a desired standard, the apparatus of the invention being usablewith a wheel of abrasive material for removing vmetal by abrasion or usable with an electric current conducting wheel or rotatable electrode for electrically disintegrating or removing metal from a Work piece or cutter through electrolytic action.

Referring to the drawings in detail and initially to FIG- URES l and 2 the apparatus illustrated therein is especially adaptable for grinding cutters or tools through the medium of an abrasive grinding wheel but is adaptable, with certain modifications hereinafter pointed out, for processing or removing metal from cutter teeth or other work piece by electric disintegration through electrolytic action. The apparatus is inclusive of a hollow bme, support or frame 10 formed of cast metal and upon which are mounted the several components of the grinding or cutter processing apparatus.

The base or frame 10 supports a plate or platform 12 provided with longitudinally extending Ways supporting a carriage or standard 14 which supports the reciprocable ram for the grinding wheel ram and associated mechanism, the platform 12 being fixedly secured to the base frame 10.

The plate or platform 12 is provided with a depending bracket 16 in which is revolubly mounted a bushing-like member 17 interiorly threaded to receive the threaded portion 18 of a shaft 19 which extends through a boss 20 formed on the base It) and is fixedly connected with a member 22 secured to and depending from the bracket 14.

The nut or bushing 17 is fashioned with a toothed or worm gear portion 24 which meshes with a worm wheel 26 mounted upon a transversely extending shaft 28 which projects through an opening in the side wall of the base and is equipped with a hand wheel 30, shown in FIGURE 2, for adjusting the ram supporting bracket or carriage 14 lengthwise of the base 10. In the embodiment illustrated in FIGURES 1 and 2, the carriage 14 forms a support upon which is pivotally mounted a reciprocable ram construction for moving a rotating grinding or metal removing wheel relative to the work piece or cutter.

The bracket or carriage 14 is provided with a transversely extending pivot shaft or trunnion 34 journalled in bearings 35 upon which is pivotally supported a housing or supplemental frame 36 which is oscillatable or swingable about the axis of the trunnion shaft 34. The housing or supplemental frame 36 is formed with interior planar bearing surf-aces or ways in which is reciprocably mounted a' ram 40 of hollow or tubular configuration and preferably generally rectangularly shaped in cross-section.

The hollow interior of the ram 40 accommodates power transmissIon means for rotating a grinding or metal disintegrating wheel. Fixedly secured at the rear end of the ram 40 is a fitting or bracket 42 fashioned with a platform 44 supporting an electrically energizable motor 46 for rotating the grinding wheel. Formed integrally with the fitting 42 is a hollow boss 48 in which is journaled a shaft 50 provided at one end with a sheave or pulley 52. The shaft of the motor 46 is provided with a driving sheave or pulley 54 which, through the medium of belts 56 rotates the shaft 50.

The forward end of the ram 40 is equipped with a fitting 60 provided with vertically disposed ways (not shown) in which is siidably mounted a head 64. The head 64 supports a fitting or bushing 66 formed with a flange 68 secured to the head 64. The head 64 is arranged to be moved by automatic means to establish a feed for dressing the grinding wheel by engaging the wheel with a truing tool or diamond at each stroke of the ram.

The bushing 66 is provided with antifriction bearings journally supporting a shaft 69 of a hub assembly 79 which provides a mounting for a rotatable member, grinding wheel or instrumentality 72 effective to remove metal from, contour or sharpen machine tools or cutters, such as those of the multi-toothed type shown at C in FIGURE 32.

The shafts 50 and 9 are connected with universal joints 73 and 74 respectively, the universal joint 73 being provided with a rod-like extension 75 which telescopes into a tube or sleeve 76, the tube having a projection 77 extending into a groove into the extension 75 to establish a drive connection between the shafts 50 and 69.

The universal joints 73' and 74 and the telescoping connection of extension '75 with sleeve 79 facilitates relative vertical movement of the head 64 during reciprocatory movements of the ram while maintaining a drive connection between the motor 46 and the wheel '72. In the embodiment illustrated in FIGURE 1, the head 64 is provided with a tubular portion 82 connected by means of a flexible tube 83 with a section blower or other means for conveying away abraded or disintegrated metal particles removed from the work piece or cutter and abrading material of the wheel.

The automatic feed mechanism for vertical progressive movement of the head 64 with respect to the fitting or support 60 for dressing the wheel will be hereinafter further described in detail. A flexible accordion-like bellows 86 is connected between the member 60 carried by the ram 40 and the forward end portion 87 of the pivotally mounted supplemental frame or bracket 36 to prevent the ingress of foreign matter or particles of metal into the region of the drive mechanism for the wheel 72. A similar bellows 89 is connected between the motor support 42 and the rear end of the supplemental frame 36 for the same purpose.

The ram 40, the motor 46 and associated drive mechanisrn, the head 64 and the wheel 72 are adapted to be reciprocated relative to the supplemental frame or carriage 36 by hydraulic means. Disposed above the ram 40 and the work piece or cutter support carried thereby.

The apparatus is inclusive of means for indexing or rotating the cutter supporting arbor 130 to bring successive teeth of a cutter into position with respect to the grinding or metal disintegrating wheel 72 to effect grinding operations successively upon the cutter teeth. Secured to the 'housing 124 is a casing or gear box 150. Journaled in bearings in the casing 150 is a transverse hollow shaft 152. Loosely mounted upon the shaft 152 and restrained against endwise movement are bevel gears 1'54 and 155. Slidably mounted upon the shaft 152 and adapted to rotate therewith under the influence of pins 150 are clutch memis a member or block 92 formed with a cylindrical bore 93 fitted with end heads 94 and 95. The end head 94 is provided with an opening provided with a stuffing gland accommodating a piston rod 97, one end of which is anchored or secured to the motor support 42, as shown in hers 156 and 157, shown in FIGURE 2, adapted for rotation with the shaft 152 but are slidable along the shaft. The clutch member 157, as shown in FIGURE 2, is in clutching engagement with the gear 155, the clutch member 156 being adapted for slidable engagement to also FIGURE 1, the other end extending into the cylinder 93 I and provided with a piston 98 reciprocable in the cylinder.

The member 92 is provided with a fitting 100 which supports a control valve 102 manipulated by a handle 104 which is adapted to control delivery of fluid under pressure for reciprocating the piston 98 and the components connected therewith. The control member 102 initiates or admits flow of fluid to a valve mechanism hereinafter described for securing continuous automatic reciprocation of the piston 98 when the valve 102 is in open posi-r tion in a manner hereinafter explained.

The base or frame 10 of the machine supports a means for mounting a multitoothed cutter C, shown in FIGURE 31, or other tool to be ground, sharpened or conform-ed effect clutching engagement with the gear 154. Mounted upon the lower end of the work supporting arbor 130 is a bevel gear 160 adapted to be selectively engaged by gear 154 or gear 155 to obtain an indexing movement of the work supporting arbor 130 in either direction.

The shaft 152 is hollow or tubular to accommodate a clutch operating shaft (not shown) which is provided with a manipulating means 162 for shifting the clutch operating shaft to selectively move clutch member 156 or clutch member 157 into clutching engagement with gear 154 or gear 155 to drive the bevel gear 160 and arbor 13%) in one direction or the other.

Fixedly secured on the transverse shaft 152 is a gear 164 which meshes with a driving worm 166 journaled within the gear box 150. The gear 166 is loosely journaled to a predetermined pattern. With particular reference to:

FIGURES 1 and 2, a vertical wall of the base 10 is fashioned with a transversely extending enlargement or boss 110 provided with a transverse recess accommodating a tang or projection 112 formed upon a cross slide or transversely slidable support 114. i

The cross slide 114 is provided with vertically arranged portions 116 provided with pairs of slots 11? and 119 accommodating securing screws 120 which may be drawn up to anchor the cross slide 114 to the base frame 16 after adjustment of the cross slide has been made. The member, 114 is provided with plates 115 which form vertical ways in which is slidably mounted a housing 124 having a hollow interior, as shown in FIGURE 1.

Disposed within the housing 124 are antifriction bearings 126 and 128 in which is journally supported a work supporting spindle or arbor 130. The upper end of the arbor 139 is provided with a disc-like table 1'52 upon which a work piece or cutter C,'shown in FIGURE 31, is adapted to be mounted during grinding or cutter-contouring operations. The arbor 130 is provided with a tenon 134 and a collar 135 for centering a cutter on the arbor. A clamping disc 136 and a clamping screw 137 are provided for securely anchoring the cutter or work piece on the table 132. Other suitable means for anchoring or mounting the cutter may be employed.

Means is provided for elevating the work supporting arbor 130 and its housing 124. Secured to a wall of the housing 124 is a tubular extension 146, shown in FIG- URE 2 in which is journally supported a shaft 142, shown in FIGURE 1, a manipulating hand wheel 143 being secured to an end of the shaft projecting from the tubular support 149. Mounted on the shaft 142 is a worm gear 144 which meshes with a driven gear 146 secured upon upon a shaft 168. Secured on a countershaft 170 is a gear 172 enmeshed with the gear 166. A spur gear 174 secured on the countershaft 179 is enmeshed with a spur gear 176 secured upon the shaft 168. The shaft 168 is connected with a universal joint 178, one component 179 of the universal joint 178 having a spline connection with a shaft or component 136 of a second universal joint 182.

Supported by the base 10 is housing 184 in which is journally supported a shaft 186. connected with the universal joint 182, as shown in FIGURE 1. Mounted upon the shaft 186 are members 188 and 1% which are actuated by means hereinafter described for effecting successive indexing movements of the work piece or cutter supporting arbor 130.

A suitable braking or friction means is provided for the work support 130. As shown in FIGURE 1, a friction band 143 engages the spindle or work support 136 and is adjustable by an adjusting screw to regulate the amount of friction to reduce lost motion or prevent overrun of the spindle or Work support 130.

A current conducting shoe or brush 158 engages a bronze ring 159 and a current conducting cable 161 connected with the brush 158 forms a circuit for the electrolytic metal disintegration system hereinafter described.

The work supporting. spindle 136 is insulated from its casing 124 by means of insulating sleeves 167 and 169, the latter sleeve being held in place by a fiber ring 171 as shown in FIGURE 19. The bevel gear is made of fiber or other insulating conducting material when the apparatus is used for electrolytic metal disintegration. Through this arrangement the work support 130 and the work carried thereby are insulated from the housing 124 of the apparatus.

Several components of the apparatus are actuated by,

10 a receptacle 194 adapted to contain a supply of oil or other fluid. Secured to wall 195 of the receptacle is a pump 196, of the conventional rotary vane type, for developing hydraulic pressure. A coupling 197 connects the pump shaft with the drive shaft of a motor 198 mounted upon a bracket 199. A filler tube 290 is provided for the tank 194. The outlet pipe 201 from the pump 196 is connected with an accumulator and relief valve 202, the tube 205 conveying the oil under pressure to the several fluid operated components. The relief valve 202 is provided with a relief vent tube 294. The return circuits or tubes of the hydraulic system are connected with a pipe 293 whereby the oil is returned from the Various components to the tank 194.

The vertically movable head or carriage 64 is provided with means for intermittently feeding the grinding wheel downwardly into contact with a wheel dressing means 320 with each reciprocation of the ram 49. The construction of head and feeding means therefor are illustrated in detail in FIGURES through 10, the feeding mechanism being utilized with an abrading grinding wheel. The head 60 is equipped with a portion 208 the latter having a central bore receiving a tenon 212 formed on a threaded shaft 214.

The shaft 214 is formed with a collar 216 seated in a recess to maintain the shaft against movement in an upward direction. Secured to the upper end of the tenon 212 is a fitting 218 provided with a polygonally shaped portion 220 adapted to accommodate a crank or other tool for manually rotating the threaded shaft 214. The memher 203 is formed with a projection 221 provided with bosses 222 adapted to accommodate a clamping screw 223 to lock the shaft 214 to the member 203.

The member 60 is provided with a boss portion 226, shown in FIGURE 9, within which is journaled a shaft 228. Formed on the shaft 228 is a worm 230 which is enmeshed with a worm wheel 232 which is formed as an integral part of a sleeve member 234 shown in FIGURE 8. An axial bore in the member 234 is threaded for enmeshment with the threaded shaft 214. The member 234, in effect, provides a nut which, when rotated, elevates or lowers the portion 208 and the head 64 upon which is journaled the shaft 69 carrying the grinding wheel 72.

The nut 234 is held in a recess formed in the portion 69 by a retaining sleeve 235 secured in position by screws 236, as shown in FIGURE 8. The shaft 228 is provided with a tenon 238 which extends into an enclosure 239 secured to the member 60. Keyed to the shaft portion or tenon 238 is a sleeve 24% which forms a component of two one-way clutches or overrunning clutch mechanisms.

As shown in FIGURES 5 and 8, the sleeve 240 is formed with two sets of pockets 242 and 244. Disposed in the pockets 242 are cylindrically-shaped clutch memhere 246 and disposed in the pockets or recesses 244 are cylindrically-shaped clutch members 243. Surrounding the sleeve 2413 at the region of the clutch members 248 is a hardened bushing 259 which is engaged by the clutch rollers or members 248. Surrounding the portion of the sleeve 240 adjacent the clutch members 246 is a gear 252. The interior surface of the gear is adapted for cooperation with the clutch members or rollers 246 as shown in FTGURES 5 and 8.

Means is provided for biasing the clutch members 246 into clutching or Wedging engagement between the interior surface of the gear 252 and the fiat surfaces of the sleeve 24$ defining the recess or chamber 242 for the clutch members 246. The sleeve 240 is formed with bores accommodating plungers 254, as shown in FIGURE 5, which are biased by springs 256 to urge the clutch rollers 246 in wedging or clutching engagement with the sleeve 249 and the gear 252.

The clutch rollers or rnern ers 248 are provided with similar biasing plungers and springs carried in bores formed in the sleeve 24% but are arranged in opposite angular relation to the angles of the biasing plungers 254 and springs 256 shown in FIGURE 5. The end of the housing 239 is closed by a cover plate or cap 241. Thus, the clutch means provided by the rollers 246 facilitates rotativc movement of the sleeve 24% and the tenon 238 on the shaft 223 when the gear 252 is moved in a counterclockwise direction as viewed in FIGURE 5 actuated by means hereinafter described.

Rotation imparted to shaft 228 rotates th worm wheel 232 to impart a feeding motion to the screw or threaded shaft 214. The clutch means embodying the rollers 242 is effective to prevent rotation of the sleeve 246 and shaft 228 in the opposite direction when the gear 252 rotates in a reverse direction to that instituting a feeding motion of the threaded shaft 214. The means for actuating the gear 252 is illustrated in FIGURES 5 through 8.

The housing 239 is formed with a cylindrically shaped portion 260 which is bored to accommodate a slidably movable member 262, a longitudinal surface region of which is formed with rack teeth 264, the rack teeth being in mesh with the teeth of gear 252. Secured to one end of the cylindrically shaped portion 269 is a sleeve 266 having a recess accommodating an expansive coil spring 268, one end of the spring bearing against an end of the rack member 262.

Secured to the rack member by a pin 269 is a rod 270 which is connected by means of a pin with a cylindrically shaped rotatable member 272. The cylindrically shaped member 272 is provided with graduations 273 which cooperate with an index at the end of a member 275. The interior of the cylinder 272 is threaded to accommodate a threaded portion 276 of the member 275 integral with the rod 27 0.

Rotation of the cylinder 272 effects a longitudinal movement to the rod 270 and the rack 262 for the purpose of adjusting the relative position of the rack member 262 to vary the extent of rotative movement of the gear 252 with each reciprocation of the slidable rack member 262. The rack member 262 is formed with a tenon or extension 280 which projects through an opening in a cover member 282 secured to the cylindrical portion 269. The shoulder 284 at the juncture of tenon 230 with the rack portion 262 limits the endwise movement of the rack in one direction.

Mounted upon an upper wall of the stationary housing 36 enclosing the ram 40 is a bracket 236. The bracket 286 is equipped with a pin 283 which provides a mounting for a member 290. The member 299 and the bracket 285 are provided with registering openings which accommodate a shear pin 292, which in cooperation with the pin 288 normally provides a fixed position for the member 298. The member 299 is formed with a boss portion 293 provided with a bore 294 in which is slidably mounted a plunger 295.

One end region of the boss portion 293 is formed with a slot 296. The plunger 295 is provided with an extension or rod portion 297, a transversely extending pin 29$ being fitted in an opening in the rod portion 297 to limit endwise movement of the plunger 295 in a lefthand direction as viewed in FIGURE 5, the pin cooperating with the slot 296 to prevent relative rotation of the plunger 295. An expansive coil spring 299 is disposed in the bore 296, the spring 299 being comparatively strong so as to normally maintain the plunger 295 in the position illustrated in FIGURE 5.

As shown in FIGURES 5 and 7, an end of the plunger 295, exteriorly of the cylindrical member 293, is provided with a slot accommodating the end of an abutment member or bar 390. The abutment or bar is pivotally connected with the plunger 295 by a headed stub shaft 361 secured to the bar 320 by a pin 302. The abutment or bar 3% is fashioned with a square shoulder portion 394 which engages the bottom surface 305' of the slot in the plunger 295 providing a stop means for normally of the rack member 262 and its extension 280.

With particular reference to FIGURES and 8, the portion 60 is provided with sockets or wells 306 which accommodate coil springs 307, the springs extending into' bores 308 provided in the portion 208.

The upper portions of the bores 308 are threaded to accommodate the threaded heads 309 formed on the upper ends of rods 310 which extend downwardly in the interior of the coil springs 307. The springs 307 serve to maintain pressure or bias on the member 208 with respect to the member 60 so as to prevent any lost motion between the threads 214 and the nut 234. The springs are of substantial length in order to accommodate the feed movements of member 208' with respect to the member 60.

"As shown in FIGURE 9, the portion 60 is provided with a tang 312 carried in ways 314 whereby the head construction 64 moves in a vertical direction effective by successive strokes of the feeding means. When the grinding machine is used with an abrasive grinding wheel, it is necessary to dress the wheel at each reciprocation of the ram and grinding stroke of the grinding wheel. As shown in FIGURE 1, a bracket 317 is secured to a member 318. The forward portion of the bracket 317 supports a. holder 319 in which is mounted the dressing diamond or dressing tool 320.

The dressing tool may be adjustably supported in order to accommodate grinding wheels of different diameters.

- The cam means for controlling the path of movement of the abrasive grinding wheel during reciprocation will be hereinafter described. The grinding wheel feeding means particularly shown in FIGURES 5 through is for the purpose of feeding the head 64 and the grinding wheel 72 downwardly in infinitesimally small increments so as to effect an engagement of the periphery of the abrasive grinding wheel with the dressing tool 320 at each grinding cycle or stroke of the grinding wheel reciprocated by the ram 40.

The operation of the feeding means shown in FIG URES 5 through 10 is as follows: A crank or other tool (not shown) is applied to the polygonally shaped portion 220 of the fitting 218, the rod 212 and the threaded shaft portion 214 rotated in a direction to adjust the head 208, the plate or head 62 and the grinding wheel 72 in a vertical direction until the periphery of the grinding wheel 72 is in a position to engage the tip of the dressing diamond 320 during a reciprocatory movement of the grinding wheel 72 and the ram '40.

The extent of the automatic downward movement of the head 64 and the grinding wheel 72 with each stroke of the ram 40 is adjusted by rotating the member 274, shown in FIGURE 5, which, through the medium of the threads 276, adjusts or establishes the position of the plunger 280 with respect to the abutment 300 carried by the member 290 supported by the stationary bracket 286. The spring 268, which is comparatively weak, is adapted to take up any lost motion in the engagement of member 274 with the threads of member 276.

The indicia on the tapered portion 273 cooperates with the index on portion 275 of the threaded member 276 to indicate the relative position or setting of the plunger 280. When the ram 40, the head 64 and the components carried by the head shown in FIGURE 5 are moved through a retractive stroke, that is, in a right-hand direction as viewed in FIGURES 1 and 5, the end of the plunger 280 strikes the abutment 300 which is held in a static position under the influence of the comparatively strong spring 299 so that the abutment 300 is relatively stationary.

10 The engagement of the plunger 280 with the abutment 300 stops or interrupts the retractive movement of the plunger 280 carried by the member 260, the latter continuing its movement in a right-hand direction as determined by the extent of movement of the ram 40 in a right-hand direction, this movement being determined by the extent of movement of the piston 98 in the cylinder 93 shown in FIGURE 1. As the movement of the plunger 280 is thus arrested, the further movement of member 260 effects a slight rotation of the gear 252 as the teeth thereof are in mesh with the rack teeth 264 on the portion 262 of the plunger 28'0.

Through the medium of the clutch rollers 246, the rotation of the gear 252 in a counterclockwise direction effects slight rotation of the shaft 228 and the worm 230 to cause slight rotation of the worm gear 232.

As the gear 232 forms an integral portion of the nut 234, the threaded shaft 214 is moved lengthwise an in finitesimally small distance, lowering the portion 208, the head 64 and the bearings supporting the grinding wheel 72. In this manner, the grinding wheel is lowered to the extent of longitudinal movement of the screw 214.

On a forward or grinding stroke of the ram 40 and the grinding wheel 72 in a left-hand direction as viewed in FIGURES 1 and 2, the clutch rollers 248, acting in a direction opposite to the clutch rollers 246, provide a holding means for preventing reverse movement of the sleeve 240, the gear 252, and the shaft 228 preventing any relative vertical movement of the shaft 214 and the head carrying the grinding Wheel.

Through the speed reduction provided by the worm 230 and the worm Wheel 232, the grinding Wheel may be dressed to the extent of only a few hundred thousandths of an inch per each grinding stroke, the extent of the feed movement downwardly of the grinding wheel being adjustable by varying the position of the adjusting means 274 shown in FIGURE 5.

A down feeding movement of the head 64 which journally supports the grinding wheel is as follows: During retractive movement of the ram 40 and grinding wheel, the bar 262 is moved in a right-hand direction as viewed in FIGURE 5 until the end portion 280 engages the abutment block 300. During this portion of movement of the ram, no rotation is imparted to the gear 252 in mesh with the toothed rack portion 264 of member 262. As the head 64 continues its retractive movement, the bar 262, remaining stationary due to its engagement with the abutment, eifects rotation of the gear 252 and a down feeding of the head 64.

The down feeding action continues until the righthand end of member 262 engages the abutment provided by member 266. Continued movement of the head 64 in a retractive direction merely compresses the spring 294.

The apparatus includes cam means for guiding the path I of an abrasive type grinding wheel during its reciprocation by the ram to establish cutting strokes or abrading strokes of the grinding wheel in engaging the cutter being round and to dress the wheel by engaging the same with the diamond 320 during each stroke or reciprocation of the grinding wheel. One form of cam means usable with an abrasive grinding wheel is illustrated in FIG- URES 1-, 13 and 31.

The cam 322 is supported upon a hardened plate 323 carried by amember or block 324, the latter being secured to the mounting plate 14 shown in FIGURE 1 spa ll the cam being held in place by a screw 5. The ram 4% is provided with a bracket or block 326 provided with a hardened cam follower 327 which cooperates with the cam 322. The cam 322 is formed with angularly arranged surfaces 329 and 330 of an angularity to guide the grinding Wheel 72 into proper engagement with the cutting faces 331 and'332 of the cutter C shown in FIGURE 31.

The cam 322 is provided with a second set of angularly arranged cam surfaces 333 and 334 for guiding the grinding wheel into engagement with the Wheel dressing diamond or dressing tool 320 during reciprocation of the ram 40. The cam 322 is maintained in a stationary position when the arrangement shown in FIGURES 1 and 31 is utilized with an abrasive type grinding wheel 72.

The apparatus of the invention is adapted to be utilized as hereinafter described 'for electric or electrolytic disintegration of metal of a cutter and for such use, a novel cam construction is provided which is shiftable or relatively movable for purposes hereinafter explained.

The shiftable cam construction and supporting means employed with the apparatus shown in FIGURE. 19 is illustrated in FIGURES 15 and 16. In this form the cam 340 and associated components are supported by member or block 335 similar in shape to the block 324 shown in FIGURES 1 and 31. The cam 340 and its supporting means are adapted for limited longitudinal reciprocation with each reciprocation of the grinding wheel 72 for a purpose to be hereinafter described.

As shown in FIGURE 15, the cam 340 is mounted in a T-shaped supporting member or cradle 342 formed with upwardly extending portions 344 engaging the ends 345 of the cam 340 to position the cam lengthwise of the member 342.

The stem 346 of the member 342 extends into a recess 348, the width of the recess being greater than the width of the stem portion 346 in order to provide for limited longitudinal movement of the member 342 and the cam 340. The cam support or carrier 342 is guided for longitudinal movement by means of side plates 356 secured to the member 335 by suitable screws 352. The cam 34% is held in place by a screw 341.

The member 335 is formed with lengthwise arranged aligned bores 354 and 355. The bore 354 accommodates a piston or plunger 356 and the bore 355 accommodates a similar piston or plunger 357. The ends of the bores are closed by plates 358 and 359. The outer end region of each of the plungers 356 and 357 is provided with a reduced tenon portion 369 providing a space to accommodate a fluid such as oil under pressure for effecting longitudinal movement of the pistons.

It should be noted that the inner ends of the pistons 356 and 357 are in abutting relation with the side surfaces of the portion 346 of the cam or template carrier 342. Each of the pistons 356 and 357 is provided with a recess accommodating a sealing ring 362. The member 335 is formed with a channel 36 in communication with a transverse fore or channel 365, a fitting 366 provided in the member 335 in communication with the channel 365 is connected with a tube 367 for conveying fluid such as oil under pressure into and away from the chamber at the end of the piston 356.

The member 335 is provided with a channel or duct 368 which is in communication with a transverse channel or duct 369 which is in communication with a fitting 370 connected with a tube 371 for conveying oil into and out of the chamber at the left-hand end of the piston 357 as viewed in FIGURE 15. Valve means, hereinafter described, is arranged to control the flow of oil into and out of the chambers adjacent the ends of the pistons ass and 357 to effect reciprocation or" the template or cam carrier 342 with each reciprocation of the ram 49 and the grinding wheel carried thereby.

The template or cammember 343 has its upper surface configurated or shaped to guide a rotatable electrode wheel 535, shown in FIGURE 19 adjacent the teeth of the cutter being processed by electric disintegration so as to m1 art a desired contour to the teeth of the cutter. In order to impart vertical motion to the electrode wheel 585 during its reciprocation, the cam follower or template follower 11 cans 327 engages the cam 349 in the same manner that the follower 327 engages the cam 322 shown in FIGURES 1 and 13.

he follower 327 being in direct engagement with the cam or template contour of the upper surface of the cam 346 is controlled by the cam surfaces to impart movement to the rain 49 and the electrode wheel 535 and component parts carried thereby about the axis of the pivot shaft 34 so as to efiect vertical movements of the electrode wheel to apply the desired contour by electric disintegration to the teeth of the cutter being ground.

Multitoothed rotary cutters have teeth of different shapes and each cutter requires a particular con-tour of cam in order to properly grind or shape the teeth. The cams are therefore readily removable to facilitate changing cams. The apparatus includes fluid pressure actuated means for elevating the ram 48 and components carried thereby and holding the ram in elevated position to facilitate the removal and replacement of a cam from the cam carrier.

One arrangement for accomplishing this purpose is illustrated in FIGURES 1 and 11 through 14. As shown in FIGURE 14, a rectangular tubular portion 37 of the stationary ram carrier 36 forms an enclosure and guide means or ways for the ram 40. The ram carrier 36 is provided with a transversely extending web portion 376 provided with an opening to accommodate a comparatively short cylinder 378.

The cylinder 378 is provided with a flange portion 380 which is secured to the Web 376 by means of screws. The upper end of the cylinder is provided with a head or closure 382. Reciprocably disposed in the cylinder is a piston 384 which is provided with a sealing ring 385 to prevent leakage of oil or other fluid along the piston. Mounted upon the plate 14 is a block or fluid distributor 388.

The distribution block 388 is for 39!} connected with an oil pressure supply line or pipe 391. The block 383 is provided with a passage 392 which is connected with a Waste or fluid return line 393 which is connected with the fluid return pipe 203, shown in *IGURE 1 on the reservoir 194. A passage 395 is in communication with the passage 390 and a valve means 396, the valve being manually operated by a finger grip member 337.

The passage 392 is in communication with a tube 399 connected with a T-shaped fitting 400 which is in con1- munication with the valve means 396 by tubes 46]; and an L-shaped fitting 402, as shown in FIGURES 11 and 12. As shown in FIGURE 12, a sleeve 463 is disposed in the tube 399 and is fashioned with a restricted passage 434 to facilitate restricted flow of fluid under pressure in the T-shapcd fitting 4% into the waste or return line 393.

A branch of the T-shape means of a tube 496 with a 33 to accommodate 13 med with a passage d fitting 400 is connected by passage in the cylinder head ow of fluid under pressure into the cylinder 378 to depress the piston 384. The operation of the ram elevating means is as follows: The manually operable valve 397 is normally maintained closed so that normally there is no fluid pressure in the tube 406 or above the piston 384. In order to depress the piston to engage the same with a portion 4% carried by the plate 14, the operator manipulates the valve 397 to admit fluid under pressure from the line or pipe 391 through pipes 4'31, T-shaped fitting 4% and pipe 496 into the upper end of the cylinder'fiiti.

Under the pressure of the fluid admitted into the cylinder, the piston 334 is forced downwardly as viewed in pawl 4S3 engaging the teeth 472 of the drum 470.

FIGURES 1, l3 and 14, engaging the piston with the upper surface of an extension 408 of block 324 or extension 408 of block 335 where the latter is employed. Downward movement of the piston rocks the ram carrier 36, the ram 40, the grinding wheel and other components associated therewith about the shaft 34 to elevate the cam follower 327 above and out of contact with the cam so as to facilitate access to the cam block carrier 323 shown in FIGURE 1, or the cam block carrier 342 shown in FIGURES 15 and 19 to remove and replace the cam.

It should be noted that the restricted passage 404 perrnits a small amount of fluid under pressure in the T- shaped fitting 400 to flow into the return line 393 but the area of the restriction 404 is substantially smaller than the area of fluid passage through the valve means 396. Thus while some fluid under pressure passes through the restriction 404, suflicient flow of fluid is established into the cylinder 378'to slowly depress the piston and elevate the ram carrier 36, the fluid pressure being maintained in the supply line while the cam is being removed and replaced by another cam.

After the interchange of camshas been eflected, the operator closes the manually operated valve 397, interrupting the "supply of fluid under pressure to the cylinder 378.

With the pressure fluid supply interrupted, the pressure on the piston 384 is relieved by flow of spent oil through the metering restriction 404 into the waste or return line 393 so that the weight of the ram carrier 36 causes the same to swing in a counterclockwise direction as viewed in FIGURES 1 and 19 to again reestablish contact of the cam follower 327 with the cam as the piston 384 is moved upwardly 'in the cylinder under the downwardly acting weight of'the ram carrier and parts or components associated therewith. Through this arrangement, movement of the ram carrier about the shaft 34- is effected through the manipulation of a single valve member 397.

FIGURES 20 through 23 illustrate a novel automatic lubricating means for lubricating the surfaces of the slidable ram 40 and its support. The lubricating arrangement for the ram is associated with a hydraulic indexing valve which is illustrated in FIGURE 23. As shown in FIGURE 22, the ram 40 is arranged for slidable movement between parallel surfaces of portions 450 of the ram carrier 36 the lower surface 452 of a housing 453 and surfaces 454 of member 36. p

The ram 40 -is provided with a block or abutment 455 which ismovable with the ram and is engageable with a plunger 456 formed with an enlarged cylindrically shaped valve portion 458 shown in FIGURE 21. A coil spring 469 is contained in the bore 461, a closure plug 462 being threaded into the entrance of the bore and forming an abutment for the spring 46%). The spring 466' normally biases the plunger 462 and valve portion 458 in a lefthand direction as viewed in FIGURE 21.

As shown in FIGURE 22, the central region 464 of ho'using453 is formed with a bore 466 accommodating a cyiindrically shaped rotatable drum or member 470', a peripheral region of the'drum 470 being formed with ratchet teeth 472. The housing 453 is provided with vertically arranged transversely spaced bores 474 and 475.

Disposed within the bore 474 is a cylindrically shaped bar or rod 476.

Disposed in the lower portion of the bore 475 is a stationary rod 47 8 and above the rod is a relatively movable plunger or rod 489. The rod 476 in the bore 474 is provided with a recess accommodating a spring plate or pawl 483 secured to the rod 476 by rivets 434, the The rod 480, which is slidable in the bore 475, is formed with a recess in which is disposed a spring plate or pawl 485 secured to the rod by rivets 486, the pawl being adapted for engagement with the teeth 472 on the drum the influence of an expansive coil spring 48-8 which abuts against a cover member 490 secured to the housing portion 453. It will be apparent from FIGURE 22 that reciprocable or slidable movements of rod 486 will effect intermittent rotation of the drum 470 and the holding pawl 483 assures rotation of the drum in only one direction, viz. counterclockwise as viewed in FIGURE 22.

The lubricating means illustrated in FIGURES 20 through 22 and 23 is associated with slidable valve means shown in FIGURE 4 which controls the hydraulic indexing of the cutter or work holder 130 shown in FIGURE 1 for moving the cutter to bring successive teeth into posi tion to be ground sharpened. As shown in FIGURE 4,

- the channel 566 is in communication with the lubricating ports shown in FIGURE 3.

, passage 510' in communication with a fluid channel 511 which is in communication with a channel 512 shown in FIGURE 22.

The valve member Silt) is formed with enlarged cylindrical portions 514, 515 and 516 which are connected by portions of reduced diameter, one portion 517 extending beyond the enlarged portion 514. The valve member 546 is slidable in the interior of the sleeve 499 and serves to control fluid flow to control the cutter indexing mechanism. The channel 504 is connected with a supply of oil under pressure supplied to the region within the sleeve 499 between the portions 514 and 515 of the valve member.

The channel 5&4 is adapted, when the valve member 500 is shifted, to move the portion 514 beyond the channel 504 to convey oil from the supply channel 5&5 into the channel 504 to operate the indexing mechanism shown in FIGURE 1. During this movement of the valve, the portion 515 blocks the channel 5&6 which conveys fluid to the indexing return mechanism 188 to rotate the work support 139 for a slight distance to bring a tooth of the cutter in engagement with the lip rest 855 shown in FIGURE 1. When the valve member 500 is moved in the opposite direction, the fluid channel 596 for the index return means 188 is placed in communication with the waste channel 520, the waste oil being returned to the reservoir 194 shown in FIGURE 1. Oil under pressure is admitted through channels 510 and 511 from the recess 528 in plunger. 458 shown in FIGURE 21 for actuating valve member 500 to a work holder indexing position.

The fluid pressure in channel 510 acts against the outer end surface of the enlarged portion 516 on the valve member 504} to move the same upwardly to initiate an indexing operation by flow of oil through the valve chamber from channel 565 to channel 504. The valve member 509 is formed with a longitudinally central channel 522 having an entrance 523 into the space between the enlarged members 514 and 516 of the valve member 503.

When flow pressure is removed from the lower surface of the enlarged portion 516, the oil under pressure from the supply channel 505 flows through the entrance port 523 and channel 522 into the region or space 524 at the end of the port-ion 517 and the oil pressure in the chamber 524 forces the valve member 500 downwardly to the position shown in FIGURE 3, to establish communication between the oil pressure supply channel 5&5 and the index return channel 506 and to connect the indexing channel 564 with the waste channel 519 to faci itate the return fiow of oil in the indexing channel to the reservoir 194.

The housing member 453 is provided with channels for conveying oil under pressure to the arrangement for establishing intermittent lubrication to the ram surfaces. The

15 channel shown in FIGURE 20 is in communication with a channel. 526 shown in FIGURE 21 which is in communication with the bore 461 accommodating the plunger 458, The plunger 453 is formed with a peripheral recess 528'which is in communication with a central channel 531"; in a portion of the plunger 553 so that when the plunger is moved in a right-hand direction as viewed in FIGURE '21, the peripheral recess 528 establishes communication of the fluid channel 526 with the peripheral recess 528, the central channel 530 in the plunger and the bore 46E.

The bore 461 is in communication with channels 532 and 533 shown in FIGURES 20 and 22 with a valve means 563 shown in FIGURE 4 which valve means is arranged for intermittent movement to intermittently establish oil pressure in the channels 532 and 533. The valve means 563 is of the spool type and is oscillated by reciprocation of the ram.

The oil channel 5$2 is in communication with the bore '475 containing the reciprocable rod 480 by a channel 535 shown in FIGURE 22. Thus, when oil pressure is built- =up in these channels under the influence of a particular position of the valve 563, the plunger 480 is moved forwardly as viewed in FIGURE 22 and, as the pawl 485 is arranged to engage the teeth on the drum 470, thedrtlm is moved through a distance of one tooth, there being preferably a large number of teeth, for example, one hundred teeth formed on'the drum.

The pawl 483, engaging the teeth on the drum 470, holds the drum against retractive movement as the plunger 480 is moved downwardly under the pressure of spring 43% when the oil pressure is relieved in the channels 435, 432 and 433 upon movement of the spool valve 534.

Thus, the drum 470, if fashioned with one hundred teeth, will be rotated one complete revolution for each one hundred complete reciprocations or cycles of the ram 40.

The drum 470 is provided at its central axis with a short bore 538 which communicates with a radial channel 539 formed in the drum. The channel 539 is adapted to register with a channel 540 formed in the housing 453 once during each revolution of the drum, the channel 540 being in communication with the bore 461. Secured to the housing 464 is a casing 541 formed with a chamber 542 accommodating a lubricant metering fitting 543 havting communication with the bore 538.

The lubricant fitting S43 is of a metering valve type of conventional construction which is adjusted or adapted to deliver a few drops of oil or lubricant into the chamber 542 during each revolution of the drum 470. The casing 541 is formed with diverging channels 545 and the adjacent region of the housing 453 is provided with channels 546 registering with channels 545 for conveying the metered oil from the chamber 542 onto the upper bearing surfaces of the ram 459. The frontal portion of the easing 541 is equipped with a closure plate bearing a sight window 548 for visual inspection.

The control for eifecting reciprocation of the ram 49 by fluid under pressure directed against the piston 98 shown in FIGURE 1 is illustrated in FIGURE 4. The master control valve 1%; ianipulated by the handle 1% initiates the operation of the machine by releasing fluid "under pressure to the arrangement shown in FIGURE 4 for reciprocating the piston 8 to reciprocate the ram 40.

As shown in FIGURE 4, a valve supporting member '92 is provided with a longitudinal bore 554, the axis of which is arranged parallel with the axis of travel of the ram it). Mounted within the bore 554 is a slidable valve member 555 which is reciprocated in the bore 554 by oil under pressure admitted alternately into opposite end regions of t .e bore 554.

Mounted upon the member 92 is a plate 558 which is provided with a transverse bore accommodating a rotatable shaft see. The member 92 is provided with a cylindrical sleeve st which is provided with openings 562 shown in FIGURE 4, Provided on the shaft 56%) and rotatable within the sleeve is a valve portion or head 563. The valve portion 563 is formed with fluid passages arranged to alternately register with a fluid supply tube 5535 from the chamber containing the master control valve 13-2 and fluid passages 565 and 566 for establishing fluid pressure alternately to the passages and to the waste line 567 to reciprocate the valve 550. The valve portion 563 is formed With an opening which registers with a fluid passage 568 formed in member 552.

Disposed longitudinally of the ram and reciprocable therewith is an operating rod 570 shown in FIGURES 2 and 4 having its forward end connected with the plate 62 so as to be reciprocated on an axis parallel with the axis of the ram. The rear portion of the rod extends through a boss portion (not shown) formed on the plate 42 at the rear of the ram to provide suitable guide means for the rod. Mounted upon the rod are abutments 572 and 574 which are adapted to engage a member 576 which is keyed or otherwise secured on the shaft 560.

The alternate engagement of the abutments 572 and 574 with member 576 causes partial rotation of the shaft 560 and the valve portion 563 in alternate directions. The fluid channel 565 is in communication with one end of the bore 554 by a channel 578, and the channel 566 is in communication with the opposite end of the bore through a channel 579. At the time of engagement of an abutment 572 or 574 with the member 576, the valve head or portion 563 is moved to a position to admit oil under pressure to flow alternately into the ends of the bore and effect reciprocable movements of the valve 556.

The enlarged portions of the rcciprocable valve 556 cooperate with ports (not shown) for controlling the ilow of oil under pressure alternately into opposite ends of the cylinder 93 to direct the piston 98 in alternate directions for reciprocating the ram 40.

The modification shown in FIGURE 19 adapts the apparatus for use in removing metal of a cutter by electric energy through electrolytic action. In the electrical disintegration or electrolytic method of dressing or shaping a cutter by the use of the arrangement shown in FIGURE 19, it is essential that the arrangement for driving or rotating an electrode wheel 585 be insulatingly supported from the adjacent structure of the apparatus as the electrode wheel driving means conducts current to the wheel for metal disintegrating purposes.

The wheel or moving electrode 585, employed in lieu of an abrasive wheel, is preferably fashioned of powdered current conducting metal and diamond particles or particles of mineral material sintered together or other types of current conducting wheel may be employed. The electric system for removing metal from the cutter does not cause any appreciable Wear of the rotating electrode wheel 535 as the wheel does not have direct contact with the cutter teeth or work piece. The system embraces the use of an electrolyte which is continuously delivered onto the wheel in a manner whereby the electrolyte is always present at the region of the wheel 535 adjacent the cutter tooth being processed.

As the periphery of the wheel 585 is not in actual contact with a cuttertooth, no appreciable heat is developed. The electrolyte bridges the small gap between the electrode wheel and the cutter tooth and is effective in conducting current for disintegrating the metal of the cutter teeth. It is believed that in the electric metal removing or disintegrating process, the surface of the cutter tooth ad' jacent t re electrode wheel is oxidized by the action of the current and in this fashion the cutter is contoured or sharpened as the metal oxide film is brushed away :by the diamond particles in the wheel.

The electrolyte preferably consists of water ffii'iifiiid with a suitable current conducting salt, such as sodium acetate, sodium citrate, sodium titrate, or ther salt. A stream of the electrolyte is delivered by a tube (not shown) onto the periphery of the wheel 585 at a region in advance of that area of the wheel in close proximity to the cutter tooth being processed.

A fluid pump 820 of conventional character is utilized to deliver the stream of electrolyte through a tube 822 onto the wheel to assure an adequate continuous film of the electrolyte on the periphery of the wheel 585. It should be noted that the periphery or operative face of the wheel 585 comprises two 'angularly arranged peripheral' surfaces 596 and 598, each surface being arranged to perform an individual metal disintegrating stroke when the wheel is moved by the ram 40' into close proximity with a cutter tooth.

In the arrangement shown in FIGURE 19, the adjustable head carrying the grinding wheel and the feeding means therefor shown in FIGURE 1, is removed from the apparatus and the plate 587 which carries the housing 588 is directly secured to the end of the reciprocating ram '40 by means of screws (not shown). An apron or curtain 584 of rubber may be provided as shown in FIGURE 19 to prevent contact of the electrolyte with the frame structure supporting the ram and associated components.

' Secured to the plate 587 is an annular disc 590 formed of nonmetallic insulating material secured to the plate 587 by means of screws 592. Disposed within the interior of the annulus 590 is a tubular member 60d provided with a flanged portion 594 which is secured to the insulating member 590, the tubular member 600 extending a substantial distance into the hollow ram 40. The end reg-ions of the tubular member 600 accommodate antifriction or ball bearings '602 and 603 which journally support a shaft or spindle 605.

The forward end of the spindle 605 is provided with a tapered portion 606 upon which is secured a hub 607 supporting the electrode wheel 585. The hub 60! is secured in position by a nut 608 threaded onto a tenon on the end of the shaft 605 Formed on the opposite end of the shaft 605 is a threaded portion 610 from which projects a tenon 611, the latter extending into a bore formed in an end of a drive shaft 612.

A bushing 614 abuts against the inner race of the bearing means 603 to properly position the spindle 605 within the tubular member 600. The bushing is carried by the threaded portion 610 of the spindle and is held in locked posit-ion by setscrews (not shown). An annular cap 616 is secured to the end of the tubular member 600 and is equipped with a sealing ring to prevent the ingress of foreign matter into the bearing supporting the spindle 605.

Disposed at the rear end of the ram 40 is a hollow housing 620, a wall 621 thereof being secured to the ram by screws 622. An upwardly extending portion or lug 623 on the housing provides an anchor for the piston rod 97 connected with :a piston 685 disposed in the cylinder 92 which is subjected to hydraulic pressure for reciprocating the ram 40'. The housing 620 is provided with an upwardly extending web portion 625 formed with a platform 626 which supports the motor 46 for driving the electrode wheel 585.

Secured to the rear of housing 6'20 is a member 628, the member '628 having a tubular portion 630 in which is mounted a sleeve 631. The sleeve 631 is provided with coun-terbores in each end region to accommodate anti friction or ball bearings 633 and 634 in which is journaied a shaft or spindle 635. The outer end of the shaft supports a sheave wheel (not shown) which is identical with the sheave wheel 52 shown in FIGURE 1 and which is driven by a belt engaging a driving sheave or pulley mounted upon the shaft of the motor 46'.

The sleeve 631 is formed of nonmetallic insulating material to insulate the spindle from the housing. The region of the shaft 635 within the housing 620 is formed with a tapered portion 637 upon which is mounted a copper ring 639 held in place by a nut 640 mounted on a 18 threaded tenon portion on the shaft 635. 'Extending axially from the threaded portion accommodating the nut 640 is a projection or tenon 642, the adjacent end region of the drive shaft 612 being split lengthwise for a short distance at the region of the tenon 612.

(limping bolts 644 extend through transverse openings in the split portions of the shaft to draw the split portions into close engagement with the extension 642 to provide intimate metallic contact between the shaft 612 and the tenon 642 to facilitate the conduction of electric current from the current conducting ring 639 to the drive or connecting shaft 612.

The opposite end of the shaft 612 accommodating the projection or tenon 6 11 on the spindle 605 is also split and the furcations drawn into intimate metallic contact with the projection 611 by bolts 646 to provide a current conducting coupling between the drive shaft 612 and the spindle 605.

The plate 628 secured to the housing 620 is provided with projections 648, one of which is shown in FIGURE 19, supporting a brush holder 650 connected with a terminal 652 connected with a source of low voltage, high amperage current. The holder 650 is provided with brushes (not shown) engaging the periphery of the ring 639 to convey current from the terminal member 652 to the ring. The brush holder is supported upon an insulating plate 654, the insulating means being supported by the projections 648.

A trough-like member 656, a portion of which is shown in FIGURE 19, is adapted to collect the electrolyte as it flows down over the cutter or work piece C mounted upon the indexing shaft 130. Means is provided for establishing a current conducting connection with the work piece carrying member or shaft 130. As shown in FIGURES 1 and 19 the housing 124 enclosing the cutter support is provided with a fitting 158 supporting a member equipped with brushes 159 engaging a bronze sleeve on the periphery of the portion 13-1 of the cutter support 130, the brushes being preferably spring biased into contact with the portion 131.

A current conducting cable 161 secured to the member C158 completes a circuit for the current delivered to the metal disintegrating electrode wheel 585 through the wheel driving shaft construction hereinbefore described.

The shiftable cam supporting arrangement illustrated in FIGURES l5 and 16 is adapted for controlling the path of movement of the metal disintegrating electrode wheel 585 in grinding the faces of the teeth of a cutter. The shiftable or movable cam arrangement makes possible the electrical disintegration of metal on one face or surface of a cutter tooth when the ram moves in a forward direction and a metal disintegrating stroke of the wheel upon movement of the ram in the opposite direction to contour or shape the other face or surface of t a cutter tooth.

- The shifting cam arrangement shown in FIGURES 15 and 16 makes possible the accurate contouring of the radius or curvature at the apex of two cutting edges of a cutting tooth as a portion of such radius is contoured by movement of the Wheel 585 in one direction and the remaining portion of the radius or curvature formed during movement of the wheel in the opposite direction under the influence of reciprocation of the ram 40.

As hereinafter described, a fluid actuated arrangement for reciprocating the ram effects traverse of the metal disintegrating wheel or electrode 585 at a comparatively slow speed during the metal disintegrating periods of its cycle and to be traversed at comparatively rapid speeds in its idle periods of traverse.

FIGURE 32 is illustrative of the path or locus of traverse of the disintegrating wheel or electrode 585 under the influence of the cam shown in FIGURE 15 exemplifying the metal disintegrating and idle movements in a complete cycle of reciprocation of the ram 40f in' removing metal from two angular faces of a cutter tooth. Considering the diagram of FIGURE 32 in connection with the contour of the cam illustrated in FIGURE 15 and the cutter tooth of FIGURE 33, the fiat portion 670 on the cam provides for guide traverse of the electrode wheel 585 through the distance identified at 670' in FIG- URE 32.

The angular facet 672 on cam 340 controls the path of traverse of the wheel through the horizontal distance indicated at 672. The region 672 is effective to grind one face 672" shown in FIGURE 33 of the cutter tooth. The ram moves at a comparatively slow rate through the metal removing stroke represented by the distance indicated at 672. The wheel 585, at the end region of this metal removing stroke, grinds one-half of the radius on the apex of the cutter tooth at the region indicated at 674" on FIGURE 32, which represents the high point of the cam shown in FIGURE 15.

At the terminus or high point of the angular cam surface 672, a fiat area 676 is fashioned on the cam 340 of a dimension lengthwise of the cam suflicient to carry or guide the wheel 585 beyond the end of the face 672" of a tooth of the cutter C by the cam follower 327 carried by the ram 40'.

The second angular guide surface 678 formed on the cam 340 is at a position such that the wheel 585 being moved further in a forward direction by the particular position of the cam 340- is guided by surface 678 in a path sufliciently spaced from the face 678" of the cutter tooth so that during this traverse of movement of the wheel represented by the distance 678 on FIGURE 32, no metal disintegrating or shaping of the cutter tooth results. During this idle period the ram is advanced at a comparatively fast rate during traverse of the wheel through the distance indicated by 678.

The ram 40' has reached its maximum forward stroke at this point and the cam support 342 and the cam 340 are rapidly shifted or moved by hydraulic means in a manner hereinafter described. With particular reference to FIGURE 15, the cam 349 is shifted from its extreme left-hand position to a right-hand position, the cam moving through a distance equal to the difference in width of the tang portion 346 of the cam carrier 342 and the width of the slot 348 formed in the supporting member 335.

This shifting of the cam 340 influences the follower 327' to effect movement of the wheel 585 toward the cutter tooth so that the periphery of the wheel 585 is shifted to a position to effect a contouring, shaping or metal removing stroke over the cutter tooth surface 678". With particular reference to FIGURE 32, the cutting stroke effective on the tooth surface 678" takes place at the first portion of the movement of the ram 49' represented by the distance 678a.

During this period of movement of the ram, the hydraulically actuated means is controlled to effect a comparatively slow movement of the ram and wheel 585 to permit proper metal disintegrating action on the surface 678" of the cutter tooth. Due to the previous shift in the position of the cam 340 at the end of the forward stroke of the ram, the flat spot 676 guides the follower 341 out of effective metal disintegrating position so that as the follower moves in a right-hand direction along the cam surface 672, the periphery of the wheel 585 is spaced from the cutter surface 672 throughout the distance indicated at 672a.

During the traverse of the cam through the distance 672a and the distance 670a, the ram is moved at a comparatively high rate of speed as no operative metal removing action is taking place. When the ram has reached its maximum point of retraction, the cam 340 is moved by hydraulic means in a left-hand direction as viewed in FIGURE 15 preparatory to a cutting stroke on a succeeding tooth of the cutter which is indexed into operative position.

During initial forward movement of the earn 340 through the distance indicated at 670' on FIGURE 32, no metal removing action occurs, hence, the ram is moved at a comparatively high rate of traverse. In FIGURE 32, the periods of fast traverse are indicated by the letter F and the slow metal removing or operative strokes or periods indicated by the letter S. It will be seen from the diagram of FIGURE 32 that the ram moves through slow traverse only during the metal removing operations performed upon the faces 672 and 678 of a cutter tooth shown in FIGURE 33. Through this arrange ment, the halves of the radius 680 at the apex of the surfaces of a cutter tooth are processed or shaped by the movements of the wheel 585 in opposite directions.

FIGURES 24 and 25 illustrate the piston and valve arrangement for actuating the ram at differential speeds to obtain ram traverse at comparatively fast and slow rates as the ram traverses the distances indicated schematically in FIGURE 32. The block or housing 92 shown in FIGURES 19 and 24 is formed with a bore 93' to accommodate a reciprocable piston 685 which is secured upon a reduced tenon portion 686 of the piston rod 97.

The distal end of the piston rod is secured to the portion 623 of the housing 620 enclosing the brush holder unit shown in FIGURE 19. A bushing 687 surrounds the rod 97' and is formed with a stuffing gland 688 to prevent leakage of fluid along the piston rod. The opposite end of the bore 93' is closed by means of a cap 689.

The region of the block 92' at one side of the cylinder bore 93' is fashioned with a plurality of channels for conveying oil or other fluid into and away from the cylinder 93' and, in certain positions of the piston 685, to direct oil through a check valve system contained in the piston. A supply channel 690 conveys oil under pressure through channels 692 and 693 to a recess 695 formed in the bushing 687. The recess 695 is of substantial area in order to provide for adequate area adjacent the piston subject to fluid or oil pressure.

A channel 697 in the block 92 which, at times, is in registration with a peripheral recess or chamber 700 formed in the periphery of the piston 685 conveys oil away from the cylinder 93'. The block 92' is provided with a channel 702 equipped with a one-way check valve arrangement 725 of a character similar to that contained in the piston 685 shown in detail in FIGURE 25 for retarding movement of the piston during one of the metal removing strokes of the electrode wheel 585. The channel 697 is in communication with a channel 698.

The block 92 is formed with a channel 704 in communication with the cylinder 93'. The channel 704 is in communication with a threaded bore containing a manually adjustable valve 708 provided with a handle portion 709.

A stuffing gland 705 surrounds the valve 708 to avoid leakage of oil along the valve member. The valve 798 is adapted to meter oil from the end of the cylinder 93 ad acent the cap 689 and is one factor in regulating the speed of the piston 685 in one period of movement.

A bore is formed in the piston which snugly receives a check valve fitting 714, shown in detail in FIGURE 25, one end of the bore being in communication with a channel 716 which opens into the peripheral recess or chamber 700 in the piston 685. The fitting 714 is formed with a comparatively large bore 718 and channels 719, 720 and 721. Disposed in the bore 718 is a ball check valve 722 which is biased toward closed position by a spring 723. The channel 719 is in communication with the bore 718 and the channel 716. The channels 720 and 721 establish communication between the bore 718 and the region in the cylinder at the left end of the piston 685 as viewed in FIGURE 24.

The ball check valve 722 is arranged to restrict oil flow from the bore 718 into the channels 720 and 721 but permits oil flow in the opposite direction through channels 721, 720, bore 718 channels 719 and 716. The admission of oil into the recess 695 in the bushing 687 moves the piston 685, rod 97 and ram 40 in a forward stroke viz. in a left-hand direction as viewed in FIGURE 24. The movement of the piston 685 in the first range, from its initial positidn illustrated in FIGURE 24, is at a comparatively high rate of traverse.

During this period the cam follower has moved through the distance designated 670' indicated in FIGURE 32.

During this period of movement of the piston 685, oil under pressure is admitted through the passages 690, 692, 693 as permitted by the position of the slidable valve 556 shown in FIGURE 4. During this period of movement of the piston, the channel 697 through the valve 556 is connected with a return oil line to the reservoir 194 shown in FIGURE 1. I

As this channel is unrestricted, the oil at the left-hand of the piston as viewed in FIGURE 24 is discharged through the channel 697 substantially unrestricted to efrect high speed traverse during the distance indicated at 670 in FIGURE 32. When the piston reaches a position covering the entrance to the channel 697 shown in FIGURE 24, the flow of oil from the left-hand of the piston is then metered out through the channel 704 past the metering valve 708 and channel 698 into the return oil line to the reservoir 194, as the check valve unit 725 in channel 702 blocks oil flow out of the cylinder through channel 702.

Thus, the piston 685 is moved at a compartively slow speed or traverse through the distance indicated by 672' on FIGURE 32. During this movement, the metal disintegrating wheel or electrode 585 is moving adjacent the face 672" of a tooth T of the cutter C, shown in FIGURE 33, to conform this face to the-desired shape.

When the piston 685 reaches a position in which the port of the channel 697 registers with the peripheral recess 700 in the piston, the piston is moved at a high rate of traverse as the oil in the cylinder at the left-hand of the piston not only moves out through the metering channel 704 but also elevates or opensthe ball check valve 722 in the piston facilitating substantially unrestricted oil flow through channels 721, 720, 719, 716 through recess 700' and channel 697 to the return line to the reservoir.

Hence, throughout the remainder of movement of the piston 685 toward the end plate 689 of the cylinder, the piston moves at a high rate of traverse and no metal removal is taking place during this period as the metal disintegrating Wheel or electrode is moved away from the other face 678" of the tooth T of the cutter C, as this face is shaped upon a return stroke of the ram 40. This phase of fast traverse of the ram is indicated at 678' in FIGURE 32.

Upon the start of the return stroke of the piston 685 and the ram 40, a period of slow traverse takes place during which period the face 678 of the tooth T is shaped or configurated by the electrolyte and metal disintegrating electrode wheel 585. When the piston 685 approaches its extreme left-hand position as viewed in FIGURE 24, the abutment or stop member 574 on the rod 570, shown in FIGURE 4, which is moved with the ram, engages the member 576 on the valve shaft 560 shifting the valve 563.to a position directing oil under pressure against the opposite end of the slidable valve 556 to move the latter to the opposite end of the bore 554, shown in FIGURE 4.

The movement of the valve 556 connects the channels 697 and 698, shown in FIGURE 24, with the oil pressure supply line and connects the channels 692 and 693 with the oil return or waste line to the reservoir. In this position, oil under pressure is metered or restricted past valve 708 and through channel 703 into the cylinder 93' at the left-hand of the piston. The valve 708 is adjusted to admit oil under pressure into the cylinder at the rate desired for the slow traverse movement of the piston.

The initial phase of movement of piston 685 in its retracting direction, that is, a right-hand direction as viewed 22 in FIGURE 24, is at slow traverse because the check valve unit 725 blocks the flow of oil from the recess 700 in the piston and the oil under pressure now existent in the channel 697 is prevented from flowing through the piston channels by the check valve 722 and the port provided by channel 702 is blocked by the piston wall.

When the piston retracts to a position uncovering the port 701- of the channel 702, the pressure of oil in channel 702 effects oil flow past the check valve unit 725 to increase the flow of oil into the cylinder 93. By thus increasing the rate of flow of oil into the cylinder 93' the piston is moved through the remainder of its retractive stroke at a high traverse speed through the distance indicated at 670a on FIGURE 32 to its initial orextreme right-hand position.

As the piston approaches this position, the abutment 574 on the rod 570 engages the projection 576 on the valve shaft 560, rotating the valve 563 and thereby directing oil under pressure to the opposite end of the cylinder 554 containing the slidable valve 556. This action directs oil under pressure through channels 692 and 693 into the right-hand end of the cylinder 93 and connects the channels 697 and 698 with the return oil line to the reservoir, and a succeeding series of fast and slow traverse movements of the piston 685 occur as above described.

The mounting of the control cam 340 shown in FIG- URES l5 and 16 and the action of shifting the cam through a small lengthwise distance with each movement of the ram 40 renders possible the shaping of the face 672 of the cutter during the forward stroke of the ram and the shaping of the face 678" of the cutter during the retractive stroke of the ram. As will be noticed in FIG- URE 33, a radius 680 joins the two cutter faces 672 and 678".

The contouring of the cam 340' coupled with lengthwise shifting makes possible the formation of the radius 680 on the cutter toooth T whereby one-half of the radius 680 is fashioned during the shaping of the cutter face 672 and the other half during the shaping of the face 678".

The apex region 676 of the cam 340 is fashioned with a short land joined with the face 672 of the cam by a radius to generate one-half the radius 680 on the cutter tooth T.

The land is joined with the cam face 678 by a radius to generate the remaining one-half of'the tooth radius 680. The horizontal land or flat surface at the apex 676 of the cam is equal in length to the lengthwise distance through which the cam 670 is moved at each stroke of the ram 40. I

Thus, on the initial cutting or metal disintegrating stroke of the electrode wheel 585 to shape or sharpen the cutter face 672", one-half of the radius 680 is also imparted to the cutter tooth C. The fiat surface or land is engaged by the follower 327' and guides the path of the wheel 585 a slight distance beyond the face 678" so that during further movement of the follower 327' along the cam face 678, the wheel 585 is spaced a sufficient distance from the cutter tooth so that no metal disintegration or removal is effected.

This occurs during the ram traverse period indicated at 672' on FIGURE 32. When the ram reaches the end of a stroke, the cam 340 is shifted in the opposite direction so that upon return stroke of the ram, the cutter surface 678 is shaped or formed together with one-half' radius 680. The flat surface on land at the apex 676 on the cam guides the follower 327 maintaining the electrodewheel 585 at a distance from the cutter surface 672 so that no further metal removing or disintegrating action takes place during the return stroke of the ram.

FIGURES 26 through 29 illustrate a counting or integrating means arranged to stop the operation of grinding by an abrasive wheel 72 of FIGURE 1 or by the metal disintegration method and arrangement of FIGURE 19 after all of the teeth of a cutter have been shaped or processed by the abrasive grinding wheel or electrode 

1. IN A METAL WORKING APPARATUS, IN COMBINATION, A BASE FRAME, A WORK PIECE SUPPORTING ARBOR MOUNTED BY THE BASE FRAME, MEANS FOR INDEXING THE ARBOR TO SUCCESSIVE POSITIONS, A SUPPLEMENTAL FRAME MOUNTED BY THE BASE FOR PIVOTAL MOVEMENT RELATIVE THERETO, A RAM RECIPROCABLY MOUNTED ON THE SUPPLEMENTAL FRAME, A HEAD CARRIED BY THE RAM AND ARRANGED FOR MOVEMENT RELATIVE THERETO IN A DIRECTION NORMAL TO THE LONGITUDINAL AXIS OF THE RAM, A ROTATABLE METAL PROCESSING WHEEL JOURNALLY SUPPORTED BY THE HEAD, HYDRAULICALLY ACTUATED MEANS FOR RECIPROCATING THE RAM, MEANS FOR ROTATING THE WHEEL, CAM MEANS ASSOCIATED WITH SAID RAM FOR EFFECTING RELATIVE PIVOTAL MOVEMENTS OF THE SUPPLEMENTAL FRAME AND SAID RAM FOR GUIDING THE PROCESSING WHEEL INTO COOPERATIVE RELATION WITH THE WORKPIECE, AND MEANS INCLUDING RACK AND PINION MECHANISM ARRANGED BETWEEN THE SUPPLEMENTAL FRAME AND THE HEAD FOR EFFECTING MOVEMENT OF THE HEAD RELATIVE TO THE RAM AT EACH RECIPROCATION OF THE RAM. 